ive been round the local lfs shops in my area and one of them is selling a twin 250 watt metal halide light .would this be over the top for my 4x2x18 aquarium as its 500 watt output, he only wants £200 for it

If you want to grow a tank of algae, thats the lighting I would use. Thats about 5.6 WPG in MH! Assumning your tank is ~ 90 gallons. You will mostly be battling algae and nutrient problems all the time with that amount.

For larger tanks, about ~2.5 wpg is a nice and balance amount of light.

If you raise the fixture away from the top of the tank by say.. 8-12" you will have fantastic lighting for a planted tank.
There is absolutely no reason why you cant use MH lighting over a planted tank, you just have to be aware of a few things like Heat, intensity etc.. some plants may react a bit to the intense non-diffused light but they will adapt.

Well yeah, if you raise the height of the lighting then it will be less a problem. I think that would be nescessary for HM becuase of the heat. So in fact it could work, but trial and error will need to find the proper height; and 500W is still alot.

wasserpest.... none of my tanks have lids exactly.. I have 3 windows open at all time. I dont need to heat my place either because I have enough lights and computer equipment running it keeps everything toasty.. lol

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

Remember Me?

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.